textproduct: Rapid City

KEY MESSAGES

- Friday will be warm and drier. Showers and thunderstorms will end over south central South Dakota in the morning, but a few thunderstorms will be possible over the Black Hills in the afternoon.

- Hot and dry Saturday.

UPDATE

Issued at 1012 PM MDT Thu Jun 4 2026

Made minor changes to pops/weather overnight and Friday morning to include better timing for chances of showers and thunderstorms. Overall, the forecast remains on track with showers ending early Friday morning over the eastern portion of the forecast area and a slight chance for a stray shower or storm during the afternoon over the Black Hills.

Temperatures on Saturday will be hot, through NBM highs may be a little too warm considering how green the grass is with all the recent rain. At the current time, will not make any adjustments but will continue to monitor model trends for future adjustments. Otherwise, the forecast remains on track with chances for showers and storms returning again on Sunday.

DISCUSSION

(This Evening Through Thursday) Issued at 122 PM MDT Thu Jun 4 2026

Upper level analysis has mostly zonal flow over the Northern Plains with a shortwave trof moving through the Rockies in Montana and Wyoming. A surface low is currently over the Bighorns with a trough extending northward into central Montana and a stationary boundary stretching across the South Dakota/Nebraska border into northeastern South Dakota. Satellite imagery is showing building cumulus clouds over northeastern Wyoming and southeastern Montana. Temperatures at 18Z were mostly in the 70s with 60s in the Black Hills.

For this afternoon and evening, convective initiation will likely begin over northeastern Wyoming and southeastern Montana as the Black Hills and South Dakota Plains remain fairly well capped. Deep layer shear around 50kts will support the potential for supercell development, with the potential for large hail. The surface boundary near the state line will drift northward later this afternoon. Moisture convergence along the boundary interacting with large-scale ascent from the approaching shortwave, will combine with deep-layer shear of 35-45kt, supporting potential storms with a more outflow dominant storm mode.

Convection will move eastward overnight. lingering into Friday morning. Temperatures will warm Friday, with highs in 80s, some 70s in the Black Hills. Shortwave ridging builds to the west, but diurnally driven showers over the Black Hills can't be ruled out during the afternoon. The shortwave ridge will move over the forecast area on Saturday, resulting in hot and dry conditions. Storm chances return Sunday as the upper level trof deepens over the western US and places our CWA under unsettled southwest flow.

AVIATION

(For the 12Z TAFS Through 12Z Saturday Morning) Issued At 523 AM MDT Fri Jun 5 2026

Friday is expected to be a sunny and warm day. So VFR conditions expected through the TAF period.

That being said, there is a low probability (~20%) of an isolated shower or thunderstorm this afternoon, primarily confined to the Black Hills. Gusty, erratic winds, lightning, and small hail are the primary threats along with transient MVFR conditions.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.